1. The Field of the Invention
The present invention relates to systems and methods for deleting objects from a wireless device. More particularly, the present invention relates to systems and methods for deleting objects from a store of a wireless device without causing a corresponding object on a synchronization partner to be deleted when the wireless device synchronizes with the synchronization partner.
2. Background and Related Art
Wireless, mobile, and other portable devices, such as personal digital assistants (PDAs) and cellular telephones, provide a user with many advantages. They are convenient to use and are easily carried on one's person. These conveniences are partially responsible for the popularity of wireless devices, which are increasing in both number and use. People are using their wireless devices to store contact information, calendar information, electronic messages, and even for Internet access. Wireless devices provide so many useful features that to many people, wireless devices are more than a convenience, they are a necessity.
Although wireless devices provide many important and useful functions, it is their size that can actually be a disadvantage, because the size and low cost of wireless devices places a practical limit on the amount of memory they have. The limited memory of wireless devices is not, however, surprising. After all, server and desktop computers also have limited memory. The major difference is that server and desktop computers typically have significantly more memory than wireless devices and are therefore able to store substantially more information.
The limited memory of wireless devices can present a problem in some circumstances, because much of the information stored by wireless devices is subject to becoming stale from the perspective of the wireless device. Electronic messages, for example, are often download from a server and opened on a wireless device. Because the electronic message is stored on the wireless device, it consumes some of the memory of the wireless device. In some instances, the user may desire to keep the electronic message in the memory of the wireless device for a short time, but the electronic message will eventually become stale and the memory will be needed for other purposes.
While the user may store the electronic message at the server indefinitely, it is not practical to indefinitely store the electronic message in the memory of the wireless device because the memory of the wireless device is limited. Similarly, calendar information often becomes stale after their corresponding dates have past. For example, a user often keeps appointments on their wireless devices. After the user has kept the appointment, however, that information is stale and no longer needed on the device, although the user may desire to keep a permanent record of the appointment on the server for future reference. Contact information can change or become outdated as well. More generally, the memory of wireless devices can become full of stale information and the user may want to delete the stale information such that new or more current data can be stored in its place.
For at least this reason, information stored on wireless devices is routinely updated or synchronized using filters that are configured to identify data that the user desires to synchronize or update. Data that is excluded by the filter is identified as stale or old data. Once the stale data is identified, it is not longer synchronized and may be deleted from the store of the wireless device. Unfortunately, many wireless devices synchronize with many different synchronization partners and deleting an object from the store of the wireless device can result in the same object being inadvertently deleted from one or more of the synchronization partners. This problem, however, does not just occur in the context of synchronization. A user may, for example, simply delete data from their device. In this case, the direct deletion of stale data can be carried over to the device's synchronization partners.
The problem, therefore, is allowing a user to delete objects from a device without deleting corresponding or replicated objects from the synchronization partners of the device. For example, assume that a user synchronizes calendar data with an office server. At a later time, the user synchronizes the calendar data with a desktop computer. During the synchronization with the desktop computer, older calendar items that are not within a synchronization filter are deleted from the store of the wireless device.
When the wireless device synchronizes with the office server at a later time, the same objects that were deleted from the store of the wireless device during synchronization with the desktop computer will also be deleted from the store of the office server. Instead of simply deleting objects from the device to free some of the memory of the device, data objects are inadvertently deleted from the office server. This is not always advantageous because people often desire to keep or archive objects, data or other information on their office servers or other synchronization partners because they typically have sufficient memory to store those objects indefinitely.